Centauri Dreams has discussed the problem of interstellar dust for fast-moving probes before. Here the issue is highlighted in a Gemini Observatory image of NGC 6559, part of the large star-forming region in the southern constellation Sagittarius. The dark structure — Gemini likens it to a Chinese dragon — is the result of cool dust that absorbs background radiation from the surrounding hydrogen gas. The region, some 5000 light years away toward the center of the Milky Way, is a reminder that in many areas, space is anything but empty.
Image credit: Gemini Observatory (using the Gemini South telescope at Cerro Pachón in the Chilean Andes).